Photographic and projecting instrument



O 6, G. GRIFFITH PHOTOGRAPHIC AND PROJECTING INSTRUIENT.

Filed Nov. 13, 1924 3 Sheets-Sheet 1 i 'TO FlL-M HI lNVENTOR OCt- 6, G.GRIFFITH PHOTOGRAPHIC AND PROJECTING INSTRUMENT Filed Nov, 13, 1924 3Sheets-Sheet 2 lNVENTOR. 0 01? INVENTOR 1924 3 Sheets-Sheet Oct. 6,1925* G GRIFFITH "PHOTOGR1PHIC AND PROJECTING INSTRUMENT Filed NOV. 13

Patented Oct. 6, 1925.

UNITED STATES 1,556,216 PATENT OFFICE.

GRAVES GRIFFITH, 0! SAN M61500, CALIFORNIA.

PEO'IOGW AND PBDJ'FBTIIG INSTRUMENT.

Application mu Iovcnber 1:, 1m Serial- Io. 749,500.

graphic and Projecting Instruments, of

which the following is a specification.

The present invention relates more particularly to photographicinstruments designed to expose consecutive sections of a film while inmotion to the action of light as received from spaced view points anddirected thereupon through the reflective agencies of fixed reflectiveelements in cooperative association with the alternate reflective actionof oppositely disposed and annularl arranged rotating reflective ele-'ments, t e images thus recorded being of stereoscopic character andcarried in vertical alignment u on a single standard film.

The essential ibatures of this invention reside in the method ofcombinin with spaced objectives and fixed reflective elements inreflective co-operation therewith, a7 revoluble reflective stem comrised of a lurality of opposite y dispos and annu arly arrangedreflective elements adapted for co-operation, at regular intervalsthroughout the revolution of the reflective system, with the fixedreflective elements for the direction of light, as transmitted by therespective objectives, upon a film while in motion.

Consequent, as an essential requirement, is the provision of meanswhereby the film may be given a velocity of movement equalling that ofthe rotating beams of light as reflected by the revolving reflectivesystem, a provision readily met through the employment of a sim lear-train adapted to impart to the fi meed member an angular velocitydouble that imparted to the revolving reflective system, a compensatingfeature rendered necessary through the optical phenomena that ra s oflight reflected by rotating reflective e ements are given a circularsweep and an angular velocity double that of the rotating reflectiveelement reflecting them.

An inherent characteristic of this instrument is its adaptability tofunction as a projection of its own crestandard character, inaddition-to that of producing stereoscopic films that may be projectedby any standard projector with relief efl'ect.

A principal object of the present invention is the provision of'opticalmeans whereby a continuity of images, as received from spaced 910Wpoints, may be recorded vertically and alternatel u on a standard, or.

other, sin le film wh1le-1n motion, and the positives ereof rojected,with stereoscopic effect, through a simple reversal of action in theseoptical means.

A further object of the invention is the provision of optical meanswhereby a continuity of-images of moving objects, as received from saced view points, may be recordedin vertical and alternate alignmentupon a continuously moving standard film, and-the positives thereofprojected, either .by reversal of action of the optical means,

or the employment for this purpose of any projecting machine of standardmake.

In addltion to the foregioing, is that of improvin upon my 00- en ing alication, filed Marih 22nd,- 1924:, Serial N d. 7O1,050, in whichsimilar objects are sought to be attained through duplication of certainoptical features and the employment of a double film.

The instrument embodies a pair of matched and spaced objectives providedwith a common focussin means and a common means for the ad ustmentoftheir optical axes relative to each other; a pair of opticallyconstituted light dividing elements;

a pair of rhomboidal-shaped ocular prisms;

a pair of oculars; an annularly arranged system of op ositely disposedreflective elements revolu l secured; a transparent cylindrical filmeeding element adapted or rotation about and without the system ofoppositely disposed reflective elements; a gear train common to both therevoluble reflective system and the trans arent cylindrical film feedingelement an adapted to rotate the former at one-half the angular velocityof the latter; a film in connection with a dispensing reel and areceiving reel; a clutch-controlled means for the intermittent actuationof the film receiving reel;

an adjustable member for framing picture sections of the film; andalight-impervious housing, provided with suitably arranged and protectedopenings through which access to its interior may be gained, withinwhich the various elements constituting the instrument are mounted andprotected. Particular attention is directed to double purpose servedthrou h the provision of optical means'for the lvision of light rays astransmitted. thereto. In eflecting this division, a combination of twoninety degree isosceles prisms are employed, these being placedhypothenusal face to hypothenusal face, with a stri of tin foil aroundthese faces to prevent t eir contacting and to afl'ord an air spacetherebetween as an element possessed of a refractive index differingfrom that of the glass in the prisms. The combinationreflective-refractive combination thus produced, being placed in the athof rays of light, with the interior reflective face at an angle ofsomewhat less than forty-five degrees to the entrant incident ray, thereresults a division, one portion of the light being reflected interiorly,while the other portion is transmitted directly thereth-rough, underoing, while in passage, refraction in equa d in opsed directions andemerging t erefrom in the line of direction of entrance.

It may be observed, in this connection, that nicety of inclination ofthe interior reflective surface of these light dividing prismcombinations, relative to the incident rays, must be effected to securerequired conditions, inasmuch as an angular inclination of this surfaceof forty-five degrees to an incident ray would result in a totalreflection of light, while a lessening of this angle to that of thecritical angle of reflection would result in its total transmission, andthat a proper medium between these two points must be sought, at whichone-half of the'li ht received will be reflected and the other alftransmitted.

It is further worthy of notice that without provisions for this airspace between hypothenusal faces, or, in other words, with these facescontacting, no such phenomena will occur, the combination, in such casebecomin the equivalent of a glass cube and possesse with all thephysical properties of one.

With light dividing means of this character dis sed and arranged for therece tion of t e light as transmitted by the o "ectives, that portionwhich is reflected will directed to and received successively by such ofthe reflective elements constituting the revoluble reflective system asare arranged for co-operative asociation therewith, and that portionwhich is directly transmitted will be received by the rhomboidal prismsco-o eratively associated therewith and directe to and throu h ocularsto an observer, the optical eatures functioning for the accomplishmentof this last being an embodiment of the prism binocular and serving forboth img. focus- I sing and keeping the photographic field ofobservation under ant observation.

It is preferred in the present construction to rely upon the retentivityof the retina for the creation of the impression of relief in thepictures viewed, as in the ordinary moving picturefor the creation ofthe impression of movement, the action here being analo us to thatobserved in viewing moving pictures taken from vehicles in motion, orfrom airplanes, where the ever changing position of the camera relativeto the ob ects photographed, under right conditions, often result in theproduction of pictures of excellent stereoscopic eflect.

In the accompanying drawin formin a part of this specification, an inwhic similar characters of reference refer to like parts, throughout,

Figure 1 is a side elevation of the instrument, as seen from the lefthand side, or the side opposite that carrying the operating crank,showin the dispensing and receiving reels, means or up-take actuation ofthe receiving reel, the objectives, a common focussing means for theobjectives, a common means for adjusting the objectives relative totheir optical axes, the oculars, the light dividing prism combinations,means for changing the angular inclination of the interior reflectivesurfaces of the light dividing prism combinations from that producingtotal reflection to that of the critical an le of reflection, or thatproducing total lig t transmission, or to varying points therebetween, asupporting base for the casing or housing, proper, this housin beingroken away exposin its interior an the relative positions of t ereflective elements comprisin the revoluble reflective tem, the revolu1e transparent cylindrical lm feeding member concentrically arrangedthereabout, the common mechanism for the actuation of these tworevoluble features, together with means for their support, and theframing member, and its actuating means, operating to frame selectedsections of the film;

Figure 2 is a front elevation of the inst-rument, showing the casing, orhousing, the adiustable means. for the su port thereof, the oculars, thereceiving ree the clutchcontrolled means for its actuation, the framingmember, the transparent cylindrical film feedin element, or member, andthe revoluble re ective system;

Figure 3 is a top plan view of the instrument, showing a portion of thehousing in section. permitting a view, in horizontal section, of thetransparent film feeding element and the reflective system, thesupporting shaft to both these features, the framing member, theoculars, the rhomboidal prisms, the light dividing prism combinations,and

the objectives, together with their common direction of travel of therays of light;

Figure 6 is a fragmentary detail of the gear train and associatedmechanisms for the rotation of the film feeding element and thereflective s stem, the gear ratios being such that the 1m feedingelement is given an angular velocity double that given the reflectivesystem.

Referring more particularly to the draw ings, my invention comprises asuitable casing, or housing, of substantially cylindrical form, adaptedfor horizontal support by means of a supporting plate 2 bearingntegrally a yoke, or arms, 3 and 3 provided with bearings 4 and 4positioned to receive trunninons 5 and 5 borne centrallyby the casingends. the outer ends of which are screw threaded to receive knurled nuts6 and 6 serving as means whereby tensional aojustment may be secured forthese members in their bearings 4 and 4. The supporting plate 2 ispivotally mounted upon a bearing plate 7 by means of a pivot bolt 8bearing 11. wing-nut 9, the bearing plate, itself, being, in turn,adapted for support by a suitable tripod, or other means, 10.

The casing, or housing, 1 is provided, interiorly, with a centrallyarranged shaft 11, supported by suitable bearing brackets 12 and 12,forming bearings about which the oppositely, alternately and annularlyarranged reflective'elements 31 and 31, constituting the revolublereflective system 14, and the transparent cylindrical film feedingelement 37 hearing peripherally sprockets 39 are adapted for rotationina common direction, in concentric paths and at compensated velocities.

The housing 1 is provided, frontally, with properly spaced objectives 15and 15 pivotally mounted in barrels 16 and 16 in such manner as topermit restricted movement about vertical axes in equal degree and inopposed directions, the barrels, themselves, being slidably borne incylindrical members 17 and 17 and provided with racks 18 and 18connecting with pinions '19 and 19 borne by a shaft 20 carrying aknurled knob 21, as ameans fortheir telescopic adjustment in focussing.The'objectives, to meet the requirements of restricted movements aboutvertical axes in adjustn'ients relative to their optical axes, arepivotally secured in the barrels 16 and 16 and provided with actuatingmeans comprising small bevel gears 22 and 22 carried by spindles 23 and23" operable through similar gears 24 and 24 borne by a shaft 25 havinga knurled knob 26.

The revoluble reflective system consists of a plurality of ninety degreeprisms 31 and 31 alternately and annularly arranged between and cementedto glass discs 30 and 30, with their hypothenusal, or reflective, facesoppositely disposed, as shown in Figure 4,

in which these faces are represented by 32 I and 32 and the entrantfaces by 33 and 33, and in parallelism between the glass discs 30 and30', the emergent faces 34 and 34 being inclined from each other at aconstant angle the degree of which is dependent upon the number ofprisms constituting the reflective system, these being of equal size andfashioned to conform to the radial requirements in their arrangement,with such portions of their surfaces as contact being cemented togetherto insure, in conjunction with the discs 30 and 30, an integral unit,the cement used, being in all cases, a transparent one, preferablyCanadian balsam.

This revoluble reflective system is carried by a centrally arrangedflanged sleeve 35, pinned, or otherwise secured, to the shaft 11 andadapted to rotate therewith.

The transparent film feeding drum 37 comprises, preferably, acylindrical glass shell, concentrically arranged without the reflectivesystem and bearing a film flange 38 having exterior sprockets 39forengagement with the perforations, formed in a standard film 40, asdispensed from a dispensing reel 65, bearing as an integral part a glassend and as a closure for the opposite end a glass disc 41, the wholecompletely housing the reflective system, as shown in Figure 3, and isloosely borne by the shaft 11, by means of a flanged member 42, havingan integrally formed pinion 43 and a sleeve 44 carrying a pulley drum45, the pulley sleeve 44 fitting over and adapted to rotate about theinner sleeve 46, forming a bearing sleeve for the framing member 47, andthrough which it is adjustable by means of the adjusting arm 48, ashereinafter described.

The framing member 47 consists of an arcuate section 49, adapted to movefreely between the reflective system and the drum flange 38 and providedwith aretangular opening 50, which serves, when brought into requiredposition. to frame such selected section of the film as may be desired,and is supported by arms 51 and 51 carried, respectively, by the sleeve46 and the shaft 11, the adjusting arm'48 being rigidly secured to theouter end of the sleeve 46 and terminating in a stud 52 adapted to bemoved through an arcuate slot 53 founded in the housing. this slot beingrendered light-proof by means of an integrally formed shield 54 carriedby the arm 48, which, also, carries the adjustably arranged framingmember 47 and is provided with a tension nut 55 whereby it is secured inadjusted position through an increased frictional contact with thehousing surface.

The film feedin drum 37 is arran ed to rotate about the s aftll and there ective system carried thereby at double the angular velocity thereof,as previously described, by

meansof a gear train 56, mountedwithin the casing, or housing, and soconnected as to operate both in common by means of a hand crank, orother means, 57. This train is shown in detail in Figure 6, and comrises the integrally formed pinion 43 carried by the drum 37 and looselymounted upon the shaft 11, the rigidly mounted pinion 58 secured to theshaft 11 and adapted to rotate the reflective system, the stub shaft 59mounted in brackets 60 and carrying, loosely, gear 61 and pinion 62secured together by a sleeve and meshing respectively with pinions 43and 58, the pinions 58 and 62 being of the same diameter, and gear 61double that of the pinion 43. The pinion 62 meshes with a larger drivinggear 63 carried by the shaft 64, which, in turn, is actuated by themeans 57.

A rotation, at any desired velocity, of the shaft 64 and gear 63 willimpart to the film feeding drum 37 an angular velocity of movementdouble that imparted to the reflective system comprised of annularly andalternately arranged reflective elements 31 and 31, a requiredcompensating movement between these two features the purpose of whichwill be more fully entered into hereinafter.

The receiving reel 65' of the instrument is actuated for film uptake bymeans of a crossed belt 66 carried by a pulley 45 and a reel pulley 67,in conjunction with a mechanism com rising a frictional spring actuateddisc c utch 68 mounted upon -a stub shaft 69, the clutch 68 beingadapted to frictionally engage the disc 70 carried by the stub shaft 71,free to rotate in the reel casing, and carrying a key 7 2 forming atight fit within a transverse slot formed in one end of spool 73, theopposite end of this spool being supported and free to rotate upon astud 74 borne by the closure cap 7 5 of the reel housing.

Reflective and refractive elements, auxiliary to those previouslyreferred to, are mounted within the housing in positions of co-operativeassociation with the objectives, the reflective system and an ocularsystem and in a common plane, these elements comprising, respectively, apair of oppositely disposed light dividing prlsm combinations 76 and 7 6constituted, each, of two ninety degree prisms 77 and 77 with opposedhypothenusal faces separated by an air film provided with a knurled knob81', the worms eing in respective engagement with the worm pinions; apair of oppositely disposed rhomboidal reflective prism elements 83 and83, positioned in co-operative relationship, respectively, with thelight dividing combinations 76 and 7 6' for the direction of suchtransmitted light as may be received therefrom to an ocular system; and-an ocular system 84 and 84' exteriorly borne b the housing, to which itisfixedly attach Normally, the intent is to give such inclination,through the mechanism provided and described, to the interior reflectivesurfaces of the prism combinations 76 and 76', as will result inone-half of the light received thereby being reflected to the revolublereflective s stem, and the other half being transmitte ceived by therhomboidal reflective elements and directed to the oculars. Obviouslythis is a provisional condition that may be departed from, either in thedirection. of total reflection, or total transmission, de-

pending upon whether the angle of inclination to the incident ray be offort -five degrees, or that of the critical ange of reflection. 1

Under the conditions, as herein provided, the revoluble reflectivesystem, while rotating, operates to reflect the light, as directedthereto, continuously upon the moving film, but, in alternation,-asreceived from opposite sides. The film having been given a circular pathwith an angular velocity equalling that of the rotating rays of lightand about the same axis of rotation, has had established, as aconsequence, therebetween a relationship the equivalent of a state ofrest, thus afl'ording exposure conditions precisely analogous to thoseof the intermittent system of present practice, while assuring, at thesame time, t at completeness of illumination in rojection, so necessartoclearness and definition of image, an not possible of attainment, infullest measure, under last mentioned conditions of practice, to saynothing of the wear and tearof both machine and film incident to thispractice.

As here presented, the instrument is of a practical size, the revolublereflective system being approximatel six inches in di ameter, comprisedof eig teen reflective elements disposed between radially arrangedplanes having alternate hypothenusa-l faces oppositely disposed relativeto their preceding hypothenusal faces, the entrant faces being confinedbetween parallel transparent discs and conforming in shape to theinclination of the planes between which they lie,

therethrough, to be reand with emergent faces at a constant angleofinclination relative each other and of an area of approximately oneinch square, 0. reflective arrangement productive of eight-- eenexposures for each revolution of the reflective system, one-half ofwhich result from the right side of the reflective act1on and the otherhalf from that of the opposite side, these being recorded in alternationand vertical alignment upon the film while in motion.

As is observable, the number of these reflective elements going toconstitute a revoluble system may be increased indefinitely by aproportionate increase of diameter of the revoluble system and decreaseof the angular inclinations of the lanes, PI'OVlSlOnS enabling such highvelocities to be attained in exposures as would prove to be beyond allossible requirements.

penings in the casing, provided with properly fitted closures, forgaining access to interiors for film removal and replacement and filmthreading are not shown, since to do so would only serve to complicatethe drawings.

Owing to the great circumferentinal contact of drum surface and film,friction may be safely and entirely relied upon to give to the film auniform feed without slippage or undue stress, but to guard against allpossibilities in that direction a limited number of sprockets arecarried by the drum and so arranged as to register at intervals withfilm perforations.

It is advised that, in all cases, the reflective faces ofall reflectiveelements, those of the combination light dividing means excepted, berendered absolutel totally light reflecting by a metallic film eposit ofgold or silver, after the ordinary silvering process, the additionalcost of which would be comparatively trifling compared with the gain inreflective efiiciency.

Having thus described myv invention, I claim, and desire to secure byLetters Patent:

1. In a hotographic instrument of the character escribed, a revolublereflective system comprised of a plurality of reflective elementscontiguously and annularly arranged, the reflective faces of which areof opposite and alternate disposition.

2. In a photographic instrument of the character described, a revolublereflective system comprised of a plurality of reflective elementscontiguously and annularly arranged, the reflective faces of which areof opposite and alternate disposition, the reflective system as a wholebeing confined between two transparent parallel discs, to which it iscementitiously secured and with which it forms an integral unit.

3. In a photographic instrument of the character described, a revolublereflective system comprised of a plurality of reflective elementscontiguously and annularly arranged, the reflective faces of which areof opposite and alternate disposition, the reflective system as a wholebeing confined between two parallel glass discs in such manner as toform an integral artthereof, with the individual reflective e ementslying between radial planes of a common angular divergence.

4. n a hotographic instrument of the character escribed, a revolublereflective s stem comprised of a plurality of reflective e ementscontiguously and annularly arranged, the reflective faces of which areof opposite and alternate disposition and the entrant facescementitiously secured between parallel glass discs, and a transparentcylindrical film feeding member concentrically arranged without saidreflective s stem and adapted to revolve therewith and t ereabout, inlike direct-ion, but at double the angular velocity thereof.

5. In a photographic instrument of the character described, spaced andoppositely disposedlight-dividing means arranged for partial andsimultaneous rotation, in equal degree and opposite directions, aboutvertical axes, and a common mechanism whereby said partial rotation maybe secured.

6. In a photographic instrument of the character described, a revolublereflective system, a transparent cylindrical film feeding memberconcentrically and revolubly arranged thereabout, and a picture framingmember of arcuate form positioned between said reflective system andsaid film feeding member and adapted to be brought into adjustedposition for framing a selected portion of the picture area.

7. In a photographic instrument of the character described, a revolublereflective system, a cylindrical film feeding member concentrically andrevolubly arranged thereabout, a picture framing member of arcuate formrotatably secured betweensaid reflective system and said film feedingmember and adapted to be brou ht into adjusted position for framing a seected portion of the picture area, a means for the actuation of saidpicture framing member, and a means carried by said' actuating meanswhereby said framing member may be secured in adiusted position, orreleased therefrom.

8. In a photographic instrument of the character described, a revolublereflective system, a revoluble transparent film feeding drumconcentrically arranged thereabout, and spaced and oppositely disposedreflective elements arranged for co-operative association, respectively,with opposite sides of said reflective system, and adapted to directrays of light, as received from opposite s aced points, alternately uponsuccessive of t e re- .elements constituting the said reflective system,as presented thereto through the rotation of said system, and spacedobjectives arranged to direct rays of light, respectively, to thesaidlight-dividing means.

10. In a photographic instrument of the character described, a revolublereflective system, a revoluble cylindrical film feedin (T memberconcentrically disposed without said reflective system, an ocularsystem, ocular .prisms in co-operative association, respectively,therewith, light-dividing means in co-operative association, res ectivelwith the said ocular prisms and, a so, wit oppo site sides of saidreflective system, and spaced objectives in respective co-o rativeassociation with the said lightividing means.

11. In a photographic instrument of the character described, a revolublereflective system, a revoluble trans arent cylindrical film feedingmember provided with'sprockets concentrlcally arranged about saidreflective system, an ocular system, ocular prisms in 00-0 erativeassociation, respectively, therewit light-dividing prism-combinations inco-operative associatlon, respectively, with the said ocular prisms and,also,

with opposite sides of said reflective system, spaced objectives inrespective co-operative association with the said light-dividingprism-combinations, a common means for simultaneously focussing saidobjectives, and a common means for the partial rotation about verticalaxes of the sald objectives, in opposed.- directions and in equaldegree, whereby the optical axes of said objectives may be alteredrelative to each other.

12. In a' photographic instrument, the combination with a casing, of arevoluble reflective system arranged within the casing, a transparentcylindrical film feeding member concentrically and revolubly arrangedwithout said reflective system and bear ng film engaging means, spacedand oppositely and adapted to frame selected ber inteiposed between saidreflective system and sai film feeding member means for adjustin' saidfilm feeding member to frame a select portion of the picture area, meansfor locking said member in adjusted tion, means for the simultaneouspartia rotation of said reflective combinations, and a common means forthe simultaneous rotation of the said reflective system and the saidfilm feeding member.

13. In a photographic instrument, the combinationtwith a casing, of arevoluble reflective system arranged within the casing, a cylindricalfilm feeding member concentricall and revolubl arranged without saidreflective system an bearing film engaging means, an ocular. system,spaced and op ositely: disposed light dividin prism com inationspivotally arranged or co-operative association, respectively, with saidocular stem and'wit opposite sides of said reective system, spacedob'ectives in respective co-o erative association with the said lightdividing combinations, a picture framing member interposed between saidreflective system and said film feeding member ortions of the picturearea, means for the ad ustment of said framing member, and a commonmeans for the simultaneous rotation of said reflective system and saidfilm feeding member in a' common direction, the film feeding memberbeing rotated atv an angular velocity double that of the said reflectivesystem.

14. In a photographic instrument, the combination with a casing, of arevoluble reflective system mounted within the casing, a cylindricalfilm feeding member concentricall and revolubl arranged without saidreflective system, sald reflective system and said film feeding memberbeing mounted to rotate about a common axis of rotation, in a commondirection, but at compensated angular velocities, a film dispensing reela film receiving reel, the said receiving reel having compensating meansadapted to take up variations due to the ever varying diameter of thereel spool, a gear train common to said reflective system and said fihnfeeding member adapted to impart relative movement thereto, and drivingmeans connecting said film feeding member and said receiving reelcompensating means.

GRAVES GRIFFITH.

